Optical waveguides, lens array and laser collecting device

Abstract

Optical waveguides, lens arrays and laser collecting devices are disclosed. The optical waveguide is formed with an output surface which is made smaller in dimension in a fast axis direction than an input surface. The waveguide collects in the fast axis direction plural laser beams output from plural laser emitting parts arranged in the fast axis direction and outputs from the output surface. The entrance surface of the optical waveguide is provided with first lenses to correspond respectively to the plural laser emitting parts. Each of the first lenses is located to be offset first predetermined distances from a corresponding one of the laser emitting parts in the beam traveling direction and in said fast axis direction, and the first predetermined distances are determined for each of the first lens in taking into account the focal length of each first lens and an angle which each first lens makes with the output surface of the waveguide.

1. An optical waveguide for receiving from an entrance surface thereof plural laser beams which travel as spreading in fast and slow axis directions and collecting the plural input laser beams in a predetermined direction to output from an output surface thereof, said waveguide being constituted such that the dimension of said output surface is made smaller in said fast axis direction than that of said input surface and that laser beams emitted from plural laser emitting parts arranged in said fast axis direction are input from said entrance surface and collected in said fast axis direction to be output from said output surface. 
   
   
     2. An optical waveguide as set forth in  claim 1 , wherein:
 the number of said laser emitting parts arranged in said fast axis direction and the distance between two adjacent laser emitting parts have been confirmed in advance;  
 said entrance surface of said waveguide is provided in correspondence to said laser emitting parts with plural first lenses for refracting and collecting laser beams entered thereinto in said fast axis direction; and  
 each of said plural first lenses is positioned with an optical axis thereof being inclined toward said output surface of said optical waveguide.  
 
   
   
     3. An optical waveguide as set forth in  claim 2 , wherein:
 each of said first lenses provided on the entrance surface of said optical waveguide is offset first predetermined distances from a corresponding one of said laser emitting parts in the beam traveling direction and in said fast axis direction, and said first predetermined distances are determined for each said first lens in taking into account the focal length of each said first lens and an angle which each said first lens makes with said output surface of said waveguide.  
 
   
   
     4. An optical waveguide as set forth in  claim 1 , wherein:
 the number of said laser emitting parts arranged in said fast axis direction and the distance between two adjacent laser emitting parts have been confirmed in advance;  
 said entrance surface of said waveguide is provided in correspondence to said laser emitting parts with plural first lenses for refracting and collecting laser beams entered thereinto in said fast axis direction;  
 each of said plural first lenses is positioned with an optical axis thereof being almost in parallel with the beam traveling direction of a laser beam input thereinto; and  
 the distances through which each said first lens is to be offset in the beam traveling direction and in said fast axis direction are determined to be first predetermined distances for each said first lens in taking into account the focal length of each said first lens and an angle which each said first lens makes with said output surface of said waveguide.  
 
   
   
     5. Optical waveguides each comprising said optical waveguide as set forth in  claim 1  for collecting plural laser beams output from plural laser emitting parts arranged in said fast axis direction and said slow axis direction, and wherein:
 the number of said laser emitting parts arranged in said fast and slow axis directions and the distances in said fast and slow axis directions between two adjacent laser emitting parts have been confirmed in advance;  
 said plural laser emitting parts are divided into plural first groups spaced from one another in said slow axis direction;  
 the dimension of each said optical waveguide is determined to be smaller than the distance in said slow axis direction between the centers of two adjacent laser emitting parts, but to be larger than the length in said slow axis direction of each said laser emitting part; and  
 plural waveguides are arranged in said slow axis direction respectively in correspondence to said plural first groups of said laser emitting parts arranged in said slow axis direction.  
 
   
   
     6. Optical waveguides each comprising said optical waveguide as set forth in  claim 1  for collecting in a predetermined direction plural laser beams which are output from plural laser emitting parts arranged in said fast axis direction and said slow axis direction, and wherein:
 the number of said laser emitting parts arranged in said fast and slow axis directions and the distances in said fast and slow axis directions between two adjacent laser emitting parts have been confirmed in advance;  
 said plural laser emitting parts are divided into plural first groups spaced from one another in said slow axis direction;  
 the dimension in said slow axis direction of each said optical waveguide is determined to be smaller than the distance in said slow axis direction between the centers of two adjacent laser emitting parts; and  
 at least two waveguides are arranged for each of said plural first groups of said laser emitting parts arranged in said slow axis direction.  
 
   
   
     7. Optical waveguides as set forth in  claim 5 , wherein:
 low refractive index members whose refractive index is smaller than that of said optical waveguides are sandwiched each between each said optical waveguide and the next thereto so that said low refractive index members and said optical waveguides are composed bodily in an alternate arrangement.  
 
   
   
     8. A laser beam collecting device comprising said optical waveguide as set forth in  claim 1 , optical fibers and a collective lens for collecting laser beams output from plural laser emitting parts, and wherein:
 the number of said laser emitting parts arranged in said fast and slow axis directions and the distances in said fast and slow axis directions between two adjacent laser emitting parts have been confirmed in advance;  
 said plural laser emitting parts are divided into plural first groups spaced from one another in said slow axis direction;  
 optical waveguides are arranged in said slow axis direction in correspondence respectively to said plural first groups;  
 entrance surfaces of said optical fibers are arranged at the output surfaces of said optical waveguides respectively;  
 said optical fibers are bundled to make output surfaces thereof arranged as desired; and  
 said collective lens is provided at the side of said output surfaces of said optical fibers;  
 whereby laser beams output from plural laser emitting parts which are arranged in said fast and slow axis directions are collected by said optical waveguides in said fast axis direction to be entered from said optical waveguides into said optical fibers respectively, and whereby the laser beams output from said output surfaces of said optical fibers are then collected by said collective lens.